Extension QDMTT return confirmed!

Already on 19 December 2023, the federal parliament approved the introduction of the new minimum tax in Belgium. This measure is intended to guarantee that companies that are part of large (international) groups always pay an effective tax rate of at least 15% in each country in which they operate. This new minimum tax applies to financial years starting on or after December 31, 2023.

In this context, the same law imposes an annual domestic top-up tax filing requirement on large groups, the so-called Qualified Domestic Minimum Top-up Tax or QDMTT in short. This QDMTT return needs be filed within 11 months after the closing date of the reporting year (which equals the financial year of the ultimate parent entity (UPE in short). As a result, the very first QDMTT return for reporting year starting from 31/12/2023 needed to be filed by November 30, 2025.

• Since the last version of the draft QDMTT return dates from June 24, 2025, there has been no official update from the Belgian tax authorities in this respect.
• Practical guidance on the information to be included and on the submission process has also not yet been published.
• On October 9, 2025, a draft bill was submitted to the Parliament with technical clarifications and corrections to the Belgian Pillar II law (see our article Pillar II: draft law contains clarifications for minimum tax).
• On October 23, 2025, an extensive Pillar 2 Circular 2025/C/68 was published, providing detailed guidance on the interpretation of the various Pillar 2 definitions as well as specific scenarios (see further discussion below).
• On November 17, 2025, the long-awaited QDMMT extension was confirmed. The new QDMTT filing deadline is 30 June 2026 for reporting years that (i) start on or after December 31, 2023 and (ii) end at the earliest on January 1, 2024 and at the latest on June 30, 2025. In the same publication, the tax authorities also inform that practical guidelines and technical documentation regarding the tax return procedure will be shared at a later stage.

Despite the lack of a QDMTT return template and without taking into account the input of the new legislative topic of October 9, the FPS Finance published a detailed circular on October 22, 2025 (2025/C/68). Below you will find a very concise overview of some attention points dealt with in this circular, taking into account it exceeds 200 pages.

Primacy of Belgian/EU legislation over OECD rules

In the event of differences between the Belgian Pillar 2 law, the EU Directive and the OECD Model rules, only the Belgian law and the EU Directive are legally binding. The OECD rules have only an interpretative function. This distinction matters, as the EU Directive and Belgian legislation differ from OECD rules on certain points, although only to a limited degree. One of the main differences is that the EU Directive also applies to large domestic groups, while OECD rules focus on multinational groups with cross-border activities only.

Local entity’s financial year differs from UPE’s financial year

Some Belgian affiliates handle a different financial year than the UPE. The circular letter clarifies that for Pillar 2 purposes, the financial year of the consolidated annual accounts of the UPE is decisive. Only if the UPE does not prepare consolidated annual accounts, the calendar year counts as the reporting year.

Intra-group compensations

The circular clarifies the treatment of intra-group settlements in the context of QDMTT and UTPR top-up taxes. Both the QDMTT surcharge and the UTPR surcharge are payable by the entire Group, not by individual local entities. In the case of several Belgian entities, the top-up tax is as a general rule levied on the entity with the highest net qualifying income in Belgium, with joint and several liability for all Belgian group entities. However, it is possible to deviate from this rule.

Additionally, groups could opt to distribute the top-up tax actually levied internally via intragroup compensations. These compensations are neutralized for tax purposes and are not considered as taxable dividends or abnormal benefits, as long as they are limited to the top-up tax amount due. This option offers extra flexibility within the group without any tax impact.

Tax credit for research and development

The circular clarifies, among other things, that the renewed tax credit for research and development investments is considered a qualified refundable tax credit for Pillar 2 purposes, since the refund will now occur after four instead of five assessment years. Furthermore, group entities will have the opportunity to choose whether or not to use or carry-forward the tax credit in those cases where an immediate use would result in their effective tax rate falling below the 15% threshold.

Transitional Safe Harbour

The OECD introduced Transitional Safe Harbour rules to limit administrative burdens. Belgium has implemented these in the Pillar 2 law of December 19, 2023. No top-up tax is due when at least one of the three tests in Article 64 of the Law of December 19, 2023 is met. These tests use available financial data or the Country-by-Country Report (CbCR). Domestic groups that typically do not submit a CbCR can also apply for these rules. The Transitional UTPR Safe Harbour applies to reporting years starting before January 1, 2026 and ending before December 31, 2026. The circular letter further explains the various tests with tangilble examples. The QDMTT return template remains however only available in draft.

QDMTT return requirement

Moreover, the circular letter emphasizes that filing a QDMTT return remains mandatory, even when no top-up tax would be due or in case a Safe Harbour applies. We refer to the website of the tax authorities for a complete overview of the circular 2025/C/68.

This extension and the additional clarifications in the circular letter are very welcome, as there are still various practical and substantive uncertainties about the QDMTT return and by extension about the P2 NOT formality. We will keep you informed as soon as the final QDMTT return template is made available. However, we strongly encourage companies to already collect all relevant data, perform the necessary calculations to ensure timely Pillar 2 compliance and make well thought choices regarding possible Safe Harbours.